Gd&t by James d. Meadows

Geometric Dimensioning andTolerancing Applications, Analysis & Measurement [per ASME Y14.5-2009] ©  James D. Meadows James D. Meadows & Associates. Inc. ASME Press Downloaded From: http://ebooks.asmedigitalcollection.asme.org/ on 07/30/2014 Terms of Use: http://asme.org/terms asme. consequential. Inc. Inc. including photocopying. this material. mechanical.com Co-Published and co-distributed by: ASME Press Three Park Avenue New York. Some illustrations in this book are copyrighted by and are the property of SolidWorks  Corporation. omissions. Meadows & Associates. nor its author guarantee the accuracy or completeness of any information published herein and neither James D. 802166 Library of Congress Number: PRE000002062 Printed in the United States of America 1 2 3 4 5 6 7 8 9 10 Printing No liability is assumed by the publisher James D. and its author are supplying information but are not attempting to render engineering or other professional services. NY 10016-5990 1-800-THE-ASME (1-800-843-2763) www asme.geotolmeadows. Meadows & Associates. Meadows & Associates.. Meadows & Associates. or exemplary damages resulting in whole or part.. Inc. D-137 Hendersonville.. Inc.© 2009 James D.org/terms . or damages arising out of use of this information. Meadows & Associates. from the readers’ use of. stored in a retrieval system. nor its author shall be responsible for any errors.. TN 37075 Phone: (615) 824-8644 FAX: (615) 824-5262 www. Web distribution.org/ on 07/30/2014 Terms of Use: http://asme.  electronic. Downloaded From: http://ebooks. No part of this publication may be  reproduced. Meadows ALL RIGHTS RESERVED including those of translation. This work is published with the understanding that James D. recording. 170 E. neither James D.org ISBN: 978-0-9714401-6-6 ASME Order No. nor its author with respect to the use of the information contained herein.asmedigitalcollection. or transmitted in any form or by any means--graphic. While every precaution has been taken in the preparation of this book. taping. Inc. The publisher and its author shall not be liable for any special. or reliance upon. Published and distributed by: James D.   Information contained in this work has been obtained from sources believed to be reliable. or  otherwise--without written permission of the publisher. Main. one  realizes that just isn’t true. apply and measure GD&T per ASME  Y14. Then I  learned that the topics that were most beneficial to allowing professionals to do their jobs more efficiently  were those that were most worthy of study and explanation. inspectors.  Writers and teachers learn over time. This is my twelfth technical book on the  subject of dimensioning and tolerancing. I’ve been  teaching and consulting on this material for about 25 years now. are evolutions of explanations given hundreds of times by teachers and  consultants trying to find the optimal way of giving our knowledge to others. I would like to thank my trusted colleagues Michael Gay. I used to believe that the most difficult topics were the ones that the most time should be spent on.  manufacturing engineers. Patty Hastie and Jeannie Winchell for their help  in putting this book into its present form. So. but also for his great patience.5-2009 standard on Dimensioning and Tolerancing. Books. It is the most comprehensive book I could have written  within the shortest number of pages. simple books sell better than long. I believe it anticipates the questions students most often worry over  and wonder about and gives them clear answers to those questions. This book covers all of the basics on how to interpret. But after more than a few blank stares.  gage and fixture design and how to read geometric controls as though the symbology was a group of  sentences trying to describe how a part functions. Readers will specifically learn the new ASME Y14.5  revision. Product designers. quality engineers. I would like to thank  Michael for his great work. But  each change makes the illustration a little better and the explanation clearer.5 symbology. The result of attaining this knowledge is  that: product representations are able to be more specific in conveying tolerancing needs. but also  to provide them with the more complex information for them to use when they realize that a little bit of  knowledge is simply not enough to do a good job.5 committee 15 years to complete. I’ve learned short. and a ton of questions. tolerance stack-up analysis.Foreword This textbook has been written for anyone whose work requires them to communicate.org/terms . rules and basic principle  revisions that took the Y14. The topics to be covered  are refined.org/ on 07/30/2014 Terms of Use: http://asme.asme. comprehensive books. Patty Hastie is a subject matter expert and a  friend. and appropriate inspection techniques are clarified. product engineers and process engineers are just a  few of the job categories that can benefit from the material. I want to give them all of the basic information. She also improves the i Downloaded From: http://ebooks. such as this one.5-2009. But I’ve also learned that the  reader of a short book is cheated with just a little bit of knowledge and lulled into a false sense of security  about their ability to apply what they have learned. inspection. she saves me from a lot of embarrassment. Even those who have been trained in GD&T  will need to be trained in these vast and sweeping changes that have been instituted into this latest Y14. At first. This book combines basic and advanced information about the principles and applications of plus and  minus tolerancing. I want the readers to have all  of the information they might need in one book. Her critiques span a  wide variety of ills from bad grammar to illustrations pasted into the wrong places. So. When she proof reads a book. and our ways of conveying them to our students and readers get better over time. Given the fact that I’ve trained tens-of-thousands of people and  consulted on thousands of projects. you try to think like a student again and anticipate the questions they  would have and then answer them before it becomes necessary for them to be asked. products can be  more easily manufactured. statistical tolerancing. geometric tolerancing. I write long books. It teaches the new Y14. many so minor few would notice the difference. He puts up with countless changes. interpret or  manufacture products through the use of engineering drawings and/or CAD models that use Geometric  Dimensioning and Tolerancing.asmedigitalcollection. I believed that knowing a thing and being able to  explain a thing were synonymous. Michael takes my crude drawings and turns them into fine  illustrations. org/ on 07/30/2014 Terms of Use: http://asme. and if there are still things that could be better.asmedigitalcollection. Jeannie Winchell is the one who takes my hand-scribbled pages and turns  them into a book. I sincerely hope the information contained in this book helps you. This book has been greatly improved by  her. She coordinates the entire project and works closely with Michael and Patty to merge  illustrations and text. James D.text and the illustrations with her knowledgeable suggestions. Meadows ii Downloaded From: http://ebooks.org/terms . She constantly proves to me that no one  should ever count solely on themselves to proof their own work. it’s probably because she told me to change  something and I chose not to.asme. 5-2009] ©  James D. Analysis & Measurement [per ASME Y14. ASME Press Downloaded From: http://ebooks.Geometric Dimensioning and Tolerancing Applications. Meadows & Associates.asmedigitalcollection.org/terms .asme. Inc.org/ on 07/30/2014 Terms of Use: http://asme. Meadows James D. asme.org/ on 07/30/2014 Terms of Use: http://asme.Table of Contents 5 Major Concepts of Geometric Dimensioning and Tolerancing --Converting from Plus and Minus Tolerance to Geometric Tolerance -Position -Profile -Selecting Datum Features -Size Tolerance Controls Form Tolerance (Rule #1). Growing Tolerance Zones 120 122 128 129 136 138 140 142 8 Profile -Profile of a Surface -New Symbol for Unequal or Unilateral Profile Tolerancing -Profile of a Line -The Power and Versatility of Profile (Mating Parts) 146 147 151 160 163 iv Downloaded From: http://ebooks. Boundary Verification -Another Difference between Bonus Tolerance (Growth) and Datum Shift (Movement) of Tolerance Zones 58 58 63 64 64 66 67 68 71 74 74 75 75 75 76 78 82 84 85 88  89 6 Form -Flatness -Straightness -Cylindricity -Circularity (Roundness) -Spherical Diameters Controlled with Circularity -Average Dimensions 93 95 100 109 113 118 119 7 Orientation -Parallelism -Parallelism of a Tangent Plane -Perpendicularity -Angularity -Angularity of a Tangent Plane -Angularity as a Refinement of Position -Shifting vs. Actual Deviation from True Position Calculations -Conversion Chart Inches -Conversion Chart Millimeters -Tolerance Zone vs. GO Gages -Flatness -Perpendicularity -Mating Part Tolerancing -Reading the Feature Control Frames as a Language -Functional Gages -Calculating Inner and Outer Boundaries -Virtual Condition -Resultant Condition -Practical Absolute Gage Tolerancing -Bonus Tolerancing Formulas -Allowed vs.org/terms .asmedigitalcollection. Two Single Segment Profile Controls -Profiling Patterns of Features Using 3 Levels of Profile Tolerances -Coplanarity -Continuous Feature of Size Symbol -Dimension Origin Symbol -Locating Offset Surface with Profile of a Surface -Conicity 163 168 173 176 177 177 180 184 187 9 Runout -Circular Runout -Total Runout -Comparison of Perpendicularity and Total Runout on a Planar Surface 191 192 195 203 10 Concentricity and Symmetry -Concentricity -Comparison of Coaxiality Controls -Symmetry 207 208 210 215 11 Datums -How They are Selected and What They Mean -Specifying Degrees of Freedom -Datum Feature Simulation -Designating Degrees of Freedom on the Part Drawing -Establishing a Valid Datum Plane -Effects of Differing Datum Precedence on Part Acceptance -Curved Surface as a Datum Feature -Conical Datum Features -Datum Feature Pattern Referenced Regardless of Material Boundary -Inclined Datum Feature -Constant Cross-Sections and Complex Datum Features -Specifying Degrees of Freedom in the Feature Control Frame -Multiple Datum Reference Frame Identification -Correct Material Boundary Size Specified Next to the Datum Feature -Correct Material Boundary Calculations -Using the Translation Modifier -Basic or BSC Spelled Out in a Feature Control Frame -Planar Datum Feature Simulated at Regardless of Material Boundary (RMB) -Planar Datum Feature Simulated at Maximum Material Boundary (MMB) -Offset Datum Features of Size Simulated at RMB and MMB -Profiled Datum Features Simulated at RMB and MMB -Irregular Datum Features of Size 217 219 223 224 227 232 237 238 239 240 241 242 243 245 246 247 248 250 252 253 255 256 263 264 265 12   Centerplane Datums -An Overview v Downloaded From: http://ebooks.asme.org/terms .org/ on 07/30/2014 Terms of Use: http://asme.asmedigitalcollection.Table of Contents -Tolerancing Mating Part Profiles -Composite Profile -Composite vs. asmedigitalcollection.Table of Contents -Centerplane Datums on Mating Parts in a Fixed Fastener Assembly 267      13         Position with Fixed Fastener Assemblies and Projected Tolerance Zones -Tolerancing Mating Parts in a Fixed Fastener Assembly -Projected Tolerance Zones and How they are Measured -Datum Feature Shift/Pattern Shift -Alternate Method Using Chain Lines to Show Projected Tolerance Zones -Calculating Clearance Hole Sizes Needed Without Projected Tolerance Zones 279 280 286 289 292 293 14  Tolerancing Mating Parts in a Floating Fastener Assembly -Floating Fastener Assembly Condition (Radial Hole Patterns) -Assigning Datum Features to Mating Parts with Radial Hole Patterns -Calculating Position Tolerance -Two Single Segment Position Tolerancing -Calculating Minimum Wall Thicknesses -Accumulative Datum Shift on Mating Parts in an Assembly -Tolerance Zones and Their Movement with Two Single Segment Position 294 295 296 298 300 301 303 304 15  Direct vs. Indirect Relationships -Overview -Tolerancing Mating Parts Holding Function Directly and Indirectly -Switching Datums in Mid-Stream -Unique Effects of Utilizing the LMC and LMB Concepts -Wall Thickness Calculations 305 306 308 311 311 314 16  Datum Targets -Flexible Parts. Datum Targets and Partial Datum Features -Sheet Metal Panels and GD&T Sheets -Equalizing Datums -Moveable Targets.asme. Finding the Datum Planes and Fixturing -Datum Target Symbols for Spherical Diameters -Centerplane Datums -Spherical Tolerance Zones 321 322 327 329 333 335 336 337 17  Datum Feature Scheme Choices -Datum Feature Patterns and Profile -Simultaneous Requirements -Compound Datum Features of Size -Secondary and Tertiary Datum Features of Size -Finished Machining Requirements for a Cast Part 338 339 342 345 347 350 18   Flexible Parts -Flexible Parts and Inspecting Them in the Way They Work -Temporary Datum Features -Common Misconceptions -Free State Variation in Sheet Metal Parts 352 353 354 355 356 vi Downloaded From: http://ebooks.org/ on 07/30/2014 Terms of Use: http://asme.org/terms . and Simultaneous Requirements -Two Single Segment Position Controls -Refining Geometric Controls to be More Cost Effective 398 399 401 402 405 411 414 22  Dimensioning and Tolerancing of Gages -Dimensioning and Tolerancing of Gages per ASME Y14. Working the Route -Calculating Inner and Outer Boundary Means and Their Tolerances 442 443 444 445 448 vii Downloaded From: http://ebooks.org/ on 07/30/2014 Terms of Use: http://asme.org/terms . Polar Coordinate Method 366 367 367 370 371 373 374 376 378 379 20  Why Use GD&T -Multiple Interpretations of Simple Plus and Minus Tolerances -Converting from Plus and Minus to Composite Position Tolerancing -Calculating the Position Tolerance for a Composite Position Control -Minimum Wall Thickness Calculation for Composite Position Tolerances -Composite Tolerancing for Coaxial Hole Patterns -Minimum Wall Thickness Calculations for Coaxial Hole Patterns -Composite Position Tolerancing with 3 Levels of Control -Differentiating Between Features of Similar Size and Shape 381 383 386 387 391 393 393 396 397 21  Composite vs.43-2003 -GO Gages -NOGO Gages -Functional Gages -Calculating to Determine Good Parts Rejected or Bad Parts Accepted -Steps in the Development of a Dimensional Inspection Plan 423 424 424 426 427 430 436 23  Tolerance Stack-Up Analysis -Tolerance Stack-Up Analysis for a Fixed Fastener Assembly -Rules -Calculating Gaps. Two Single Segment Positional Tolerancing -Similarities -Differences -One Level Tolerancing vs. Boundary Concept Explanation -Rectangular Tolerance Zones for Round Holes -Bi-directional Position Tolerancing.Table of Contents -Specifying Restrained State Inspection -Fixturing Sheet Metal Parts -Profile ALL OVER Controls and What They Mean 358 359 363 19  Position Boundary Concept -Position Boundary -Elongated Holes -Functional Gages and Virtual Condition Boundaries -Tolerancing Hoses.asmedigitalcollection. Two Single Segment Positional Tolerancing -Composite vs. Composite Tol. Pipes and Tubing with Positional Boundary -Tolerancing Oddly Configured Features with Positional Boundary -Oddly Configured Datum Features and How to Represent them in Gages -Tolerance Zones vs.asme. asmedigitalcollection. Normal Distribution of Tolerance and the Standard   Deviation.Table of Contents -Calculating Statistical Toleranclng -Root Sum Squares -Bender Factor -Reintegrating the Statistical Tolerancing into the Assembly -A Simpler Way to Reintegrate the Statistical Tolerance -More Statistical Formulas and Symbols -Glossary of Statistical Terms 24  How to be Specific in Calculating and Specifying Statistical Requirements    for Size and Geometric Tolerancing -Some Useful Definitions When Geometric Tolerances are Used -Symbology for SPC Formulas -Arithmetic Mean.asme. Non-factors -Alignment -Dealing with Threaded Features -Calculating the Pertinent Numbers -Simplifying the Assembly Drawing -Creating a Line Graph with Numbers to Calculate the Minimum Clearance -Adding the Negative and Positive Designations -Wall Thickness Calculations and Choosing the Pertinent Tolerances -Single Part Analysis -Using Profile Tol.org/terms . Statistical Probability for Tolerance Stack-Up Analysis for   Positional Geometric Tolerances -Calculating a Standard Deviation -Predicting the Amount of Tolerance to be Consumed by Manufacturing -Charts and Tables 451 451 457 458 461 462 464 466 469 471  474 476 477 478 25  Tolerance Stack-Up Analysis in a 5-Part Assembly -Determining a MIN GAP in a Rotating Assembly -Factors vs. and Separate Requirements for Accumulated Error 481 482 483 485 486 490 491 492 492 493 496 499 26  Tolerance Stack-Up Created during Manufacture due to Changing Set Ups  -Where the Tolerance Accumulation Comes From -Proportions and Trigonometry 502 503 504 27   GD&T as a Language  -To Properly Read a Drawing -Reading the Feature Control Frames as Sentences -Profile -Tolerance Zones and Pattern Shift Zones -Reading Two Single Segment Controls -Using Gages to Visualize a Geometric Tolerance’s Meaning -Reading a GD&T Sheet -Optional Tolerancing Approaches for Similar Results -Gears 507 508 512 513 513 514 517 526 529 530 viii Downloaded From: http://ebooks.org/ on 07/30/2014 Terms of Use: http://asme. Where it Comes From and How it Effects the Workpiece -Bonus Tolerance.Table of Contents -Pattern Shift.asmedigitalcollection.org/ on 07/30/2014 Terms of Use: http://asme.asme. Meadows 574 ix Downloaded From: http://ebooks. Virtual Condition and Zero Positional Tolerances -Threads. Gears and Splines -Sequential Tolerancing Using the Simultaneous Requirement Rule 28  Definitions 532 535 536 537 539            Index 568            Bibliography 573            Other GD&T Course Materials Written by James D.org/terms . asmedigitalcollection.asme.org/ on 07/30/2014 Terms of Use: http://asme.Downloaded From: http://ebooks.org/terms .